TY - CHAP M1 - Book, Section TI - Immediate Hypersensitivity A1 - Yazdany, Jinoos A1 - Manno, Rebecca L. A2 - Papadakis, Maxine A. A2 - McPhee, Stephen J. A2 - Rabow, Michael W. A2 - McQuaid, Kenneth R. Y1 - 2022 N1 - T2 - Current Medical Diagnosis & Treatment 2022 AB - IgE antibodies occupy receptor sites on mast cells. Within minutes after exposure to the allergen, a multivalent antigen links adjacent IgE molecules, activating and degranulating mast cells. Clinical manifestations can be explained by the effects of released mediators on target end organs. Both preformed and newly generated mediators cause vasodilation and permeability changes, visceral smooth muscle contraction, mucous secretory gland stimulation, vascular permeability, and tissue inflammation. Arachidonic acid metabolites, cytokines, and other mediators (such as chemoattractants) induce a late-phase inflammatory response that appears several hours later in affected tissues when antigen exposure is continuous (eg, pollen) or chronic. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1184193759 ER -